1. Field of the Invention
The present invention relates to new compositions that may be cured by radical polymerization at room temperature and contain olefinically unsaturated polyesters and to their use for the production of coating, patching or sealing compositions or for the production of molded articles.
2. Description of the Prior Art
Known binders based on unsaturated polyesters contain .alpha.,.beta. ethylenically unsaturated polyesters and monomers copolymerizable therewith. As monomer, styrene is used almost exclusively. Styrene evaporates during processing, which necessitates the expensive purification of the air of the fabrication shops and the waste air of the drying plants.
It has previously been attempted to make available olefinically unsaturated compositions that contain compounds having both (meth)acryloyl groups and partially acrylated polyhydric alcohols, and whose non-esterified hydroxyl groups have been etherified by (meth)allyl alcohol or benzyl alcohol (DE-OS 2,736,627) amenable to curing with metal salts of siccative acids and hydroperoxide. For practical application, however, still shorter curing times are necessary or desirable than are achievable with these systems.
DE-OS 3,319,013 describes di- or polyesters which contain (meth)acryloyl groups and are based on (meth)acrylic acid and alkoxylated 2-butene-1,4-diol. These polyesters may be cured by radiation and also by curing with metal siccatives and hydroperoxides into crossolinkable products. However, because they are produced by azeotropic esterification, only limited variations of the composition and therefore of the properties of the binders produced therefrom is possible. Simultaneously, problems arise from unreacted (meth)acrylic acid as well as from low molecular weight esters of (meth)acrylic acid that can be formed by transesterification from constituents of the polyester. A great disadvantage of such compounds is known to be their toxicity and volatility.
It is an object of the present invention to make available systems that are radical-curable by (hydro)peroxides even at room temperature, that are suitable for the production of monomer-free radical-curable coating compositions or patching compositions as well as molded bodies and that are also equal with regard to the technical properties to the systems of the prior art mentioned without having their disadvantages.
Surprisingly, it has now been found that these objects may be achieved with the .alpha.,.beta.-ethylenically unsaturated polyesters A) which are described in more detail hereinafter or mixtures of these polyesters with compounds B) having (meth)acryloyl groups and/or vinyl ether groups. Polyesters A) are based on a) .alpha.,.beta.-ethylenically unsaturated dicarboxylic acids and/or their anhydrides and b) alkoxylated 2-butene-1,4-diol. They can be cross-linked both by means of radical formers, such as peroxides, and also by radiation curing.